Recently, a fifth-generation cellular system has been reviewed as a successor to the fourth-generation cellular systems such as Long Term Evolution (LTE).
The adoption of a new radio access technology (RAT) in addition to the existing LTE system has been reviewed in the fifth-generation cellular system. A frequency band higher than the frequency bands (cellular frequency bands) used in the LTE system will be used to implement high-speed wireless communication in the new radio access technology.
Antennas of two different types, i.e., an antenna for a lower frequency band (cellular frequency band) and an antenna for higher frequency bands are therefore required for a wireless device conforming to the fifth-generation cellular system. This matter may be a cause for increasing antenna implementation space which should be secured in the wireless device.
Thus, a new antenna structure which can suppress increase in antenna implementation space is required.